US5284615A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for making injection molded soft magnetic material
Assignee: Mitsubishi Materials Corp
•
Filing: 1992-07-15
•
Granted: 1994-02-08
•
Expires: 2012-07-15
Abstract
Abstract The present invention presents a method of processing ferrous powder materials to produce small component parts exhibiting excellent soft magnetic properties, in particular, residual magnetic flux density. The processing steps involve, in part, mixing with a binder, dewaxing or presintering at a temperature higher than in the conventional dewaxing process, followed by final sintering and a further conversion sintering, at a temperature lower than in the conventional sintering process, to produce parts having density values of over 96% theoretical density and excellent soft magnetic properties. The invented method is suitable for producing small component parts having sufficient strength and excellent soft magnetic properties to make them suitable for miniaturized electrical and electronic equipment.
Inventors
- 👤 Koshiro Ueda
- 👤 Mutsumi Moribayashi
- 👤 Tohru Kohno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:15
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/10; B22F3/1017; B22F3/1021; B22F1/00; B22F1/10; B22F1/108; B22F3/22; B22F3/225; C; C22; C22C; C22C33/00; C22C33/02; H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/14; H01F1/20; H01F1/22; H10; H10W; H10W99/00; B22F2998/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
173 words
A method for making injection molded component parts having properties suitable for soft magnetic applications in small electrical and electronic equipment, said method comprising the steps of: (a) hot mixing a ferrous powder with a thermoplastic binder at a concentration between 8-15 weight % to product a powder mix; (b) cooling said powder mix to room temperature and subjecting said powder mix to a granulation process to produce a feed particle mix for injection molding; (c) injection molding said feed particle mix to produce molded parts; (d) dewaxing said molded parts of step (c) at a temperature between 680°-750° C. to produce presintered parts containing not more than 0.05 weight % carbon produced from said binder; (e) subjecting said presintered component parts of step (d) to final sintering at a temperature of between 870°-910° C.; and (f) subjecting said component parts of step (e) to a conversion sintering step at a temperature of 1050°-1350° C. to impart soft magnetic properties to said component part; thereby producing injected molded parts having soft magnetic properties.
Claim 2
Independent Claim
173 words
A method for making injection molded component parts having properties suitable for soft magnetic applications in small electrical and electronic equipment, said method comprising the steps of: (a) hot mixing a ferrous powder with a thermoplastic binder at a concentration between 8-15 weight % to product a powder mix; (b) cooling said powder mix to room temperature and subjecting said powder mix to a granulation process to produce a feed particle mix for injection molding; (c) injection molding said feed particle mix to produce molded parts; (d) dewaxing said molded parts of step (c) at a temperature between 680°-750° C. to produce presintered parts containing not more than 0.05 weight % carbon produced from said binder; (e) subjecting said presintered component parts of step (d) to final sintering at a temperature of between 870°-910° C.; and (f) subjecting said component parts of step (e) to a conversion sintering step at a temperature of 1050°-1350° C. to impart soft magnetic properties to said component part; thereby producing injected molded parts having soft magnetic properties.
References Cited (Backward Citations)
EP0324122A1
Cited
EP0379583A1
Cited
US5055128A
Cited
US5098648A
Cited
US4964907A
Cited
US5067979A
Cited
US5002728A
Cited
US5032355A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-02-07 | 1997-08-09 | 1998-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-07 | 2001-08-09 | 2002-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-07 | 2005-08-09 | 2006-02-08 | $7700.00 | Window Closed / Lapsed |